对电磁流量计中干扰问题的讨论

在简要阐述了电磁流量计的几种励磁方式的基础上,分析了低频矩形波励磁技术中常见的干扰及其影响,提出了相应的处理措施,以保证电磁流量计的稳定运行.     

对电磁流量计中干扰问题的讨论

在简要阐述了电磁流量计的几种励磁方式的基础上,分析了低频矩形波励磁技术中常见的干扰及其影响,提出了相应的处理措施,以保证电磁流量计的稳定运行.     

一种低功耗电磁流量计的设计

本文对电池供电的电磁流量计进行了初步研究.根据被测信号的特点,即微弱信号在强干扰下的测量原理,对主要组成部分进行了低功耗设计,使电磁流量计可以实现便携式低功耗的工作要求.     

电磁流量计干扰分析与对策

根据电磁流量计的测量原理,结合电磁流量计实际应用中遇到的正交干扰、微分干扰、工频干扰等问题,分析干扰产生的原因,提出采用同步采样技术、采样时间长度选择、数字滤波技术等方法,从根本上对这些干扰信号进行抑制和消除,使电磁流量计更适应于现场应用。     

电磁流量计的智能化

电磁流量计的智能化开封仪表厂张稚，韩书芳智能化电磁流量计是一种以计算机技术为核心的自动测试系统（ＡＴＳ）。有显示数字化、计算与控制软件化和运行参数可编程及以下特点：１．提高励磁技术水平，改善测量性能励磁技术是衡量电磁流量计测量性能的关键技术之一。电磁...     

电磁流量计在酸性废水处理中的应用

介绍Khrone公司生产的电磁流量计在不锈钢酸性废水处理中的应用,探讨了电磁流量计的测量原理和结构,以及安装技术要求和常见的故障,对于掌握该流量计的使用方法和性能具有一定的指导作用,为电磁流量计在线测量提供了一定的参考。     

电磁流量计干标定技术

介绍电磁流量计干标定技术的研究现状及工业化应用前景,阐述电磁流量计干标定原理.指出如何准确测量有效区域内各点磁场信息是电磁流量计干标定技术工业化应用的关键技术,利用电磁流量计磁场的交变特性,通过测量电磁感应所产生的其他物理量间接获取电磁流量计有效区域内磁场信息,是解决此关键技术的有效途径,并以此为基础重点分析了涡电场测量法与面权重函数法这两种新型干标定方法的测量原理、特点及实现方法.此项技术为我国开展电磁流量计干标定技术的研究及工业应用提供技术参考.     

高温低功耗电磁流量计的研制

通过对电磁流量计测量技术发展的分析，认为如从小型、低功耗和高温作为切入点，通过特殊设计的磁场结构，多参数测量等手段和方法将是对电磁流量计的创新。以此思想设计并制造出了一种主要用于油田注水井注水流量测量的新型流量计。     

HB3603系列电磁流量计的研制

为进一步提高电磁流量计的应用范围及测量精度,研制了HB3603系列电磁流量计,介绍了该系列流量计的工作原理及关键设计技术.该系列流量计具有结构合理、功能齐全、测量准确等技术特点,可广泛应用于各类工业现场.     

便携式低功耗电磁流量计测量电路的设计

本文对低功耗电磁流量计的测量电路进行了研究,给出了测量电路的基本组成。根据被测信号的特点,即微弱信号在强干扰下的测量,阐述了测量电路的工作原理。本测量电路主要用于电池供电的电磁流量计中,可以实现便携式低功耗的工作要求。     

基于ANSYS的电磁流量计建模研究

励磁系统是电磁流量计的关键部分,励磁方式和励磁参数的合理设置对电磁流量计的性能有重大影响.以前由?乏电磁流量计模型,开展相关研究非常困难,因此电磁流量计建模一直受到研究人员的关注.本文利用有限元方法建立?量计传感器场路耦合模型,根据有限元数值分析功能求解感应电势信号,模拟电磁流量计的动态性能.实验结果表明,模?真信号与理论波形近似,建立的模型有效.该模型可以作为研究励磁系统的辅助手段,提高研究效率.     

船舶气象仪的电磁兼容设计

为确保船舶气象仪在复杂的电磁环境中正常可靠工作,提高其抗电磁干扰能力,并尽可能地减小自身电磁干扰的产生,对其进行了电磁兼容设计。电磁兼容设计的原则与思想贯穿了设备的电路设计、元器件选择和结构工艺布局等各个过程。采取的各项技术措施也在实验中得到了充分验证。     

工业变频器电磁干扰现象分析及其抑制

为防止电磁干扰对变频器产生负面影响,实现变频器在工业自动化应用系统中稳定、可靠、安全地运行,通过对变频器电磁干扰源及其干扰途径进行分析,提出了防、抗电磁干扰的实际解决方法,给出了在变频器应用系统设计和安装中抑制干扰的具体措施,降低或消除了电磁干扰对变频器的影响。实践表明,该电磁干扰抑制方案为变频器在工业自动化应用系统中稳定、可靠、安全运行提供了保障,满足了工业变频器日常运行的需要。     

Relationship between velocity profile and distribution of induced potential for an electromagnetic flow meter

This paper investigates the relationship between the induced electric potential and the velocity distribution of the conductive continuous phase in two-phase flows in pipes to which an electromagnetic field is applied, with a view to measuring the continuous phase velocity profile. In order to investigate the characteristics of an electromagnetic flow meter in multiphase flow, an alternating current electromagnetic flow meter was modelled using FEMLAB software. Using the model, electrodes could be placed at any position on the insulating internal surface of the flow meter to satisfy the requirement of measuring the induced potentials at specific locations at the boundary of the flow. The induced electric potential or potential differences from the electrodes were analysed for various simulated flow conditions. The numerical simulation results suggest that electromagnetic flow metering may be an effective novel method for measuring the axial velocity profile of the conducting continuous phase. Furthermore, when combined with the local volume fraction distribution of the continuous phase (obtained, for example, using Electrical Resistance Tomography, also known as ERT), it is expected that the measured continuous phase velocity profile would enable the volumetric flow rate of the continuous phase to be obtained.     

Calculation of the virtual current in an electromagnetic flow meter with one bubble using 3D model

Based on the theory of electromagnetic induction flow measurement, the Laplace equation in a complicated three-dimensional (3D) domain is solved by an alternating method. Virtual current potentials are obtained for an electromagnetic flow meter with one spherical bubble inside. The solutions are used to investigate the effects of bubble size and bubble position on the virtual current. Comparisons are done among the cases of 2D and 3D models, and of point electrode and large electrode. The results show that the 2D model overestimates the effect, while large electrodes are least sensitive to the bubble. This paper offers fundamentals for the study of the behavior of an electromagnetic flow meter in multiphase flow. For application, the results provide a possible way to estimate errors of the flow meter caused by multiphase flow.     

浅谈电子称重仪表现场应用中的电磁干扰及其防护

在各种工业生产环境下，电子称重仪表的广泛应用，都需要电子称重仪表有着可靠的性能。这也给各个仪表生产商提出了新的要求，即在恶劣的电磁环境下，仪表能否抵抗外界的电磁干扰而正常可靠的工作。本文列举了三种工况下最常见的电磁干扰并对其进行分析，并提出一些简单有效的防护措施，供各位读者参考。     

电磁流速仪在水文测验中的应用

水文测验中的关键参数——水流流速能否准确、及时地测量,直接影响到测验成果精度,为了提高测验精度,本文介绍了一种新型仪器——电磁流速仪,它可替代传统转子式流速仪,具有使用寿命长,不怕水中漂浮物缠绕和流冰碰撞等优点。     

电磁式浪潮流仪测量方法及结果分析

海流是基础的海洋资料,海流计是海洋水文测量的重要设备。本文简单介绍了海洋环流的成因和分类,阐述了电磁式浪、潮、流仪的工作原理,着重介绍了电磁式浪、潮、流仪流速和流向的计算方法,通过测量数据结果并以曲线的方式分析该型设备的工作性能。     

Calculation and measurement of the magnetic field in a large diameter electromagnetic flow meter

An idealized magnet model previously used in a simple coil configuration is applied to a more complicated engineering design problem, where an electromagnetic flow meter in diameter of 500 mm is used with five pairs of coils. The numerical results are compared with measurement data. The difference between theory and experiment and the possible causes of errors are discussed. It is shown that the idealized magnet model is practical for the design and the analysis of the flow meter. The work also shows that the traditional uniform field design based on two dimensional (2D) analysis is not suitable for this kind of flow meter. Thus nonuniform field and 3D analysis is needed.     

Errors in electromagnetic flow meter with magnetic particles

Magnetic admixtures change the magnitude and distribution of the magnetic field and virtual current in active fluid volume of electromagnetic flow meter, and measurement error appears. The value of error depends on the concentration, permeability and electric conductivity of magnetic admixtures and on the form of particles.The principles of error formation are investigated assuming that in the fluid with uniform properties there may be a small concentration of spherical particles, whose magnetic and electric properties are different from that of the fluid. An ideal electromagnetic flow meter with a rectangular duct and infinitely conductive large electrodes is assumed. The flat velocity profile is supposed. Measurement error is evaluated using the analogy between electrostatic, magnetic and electric current fields. The main causes of measurement error are examined. There is a deviation of densities of virtual current and magnetic flux inside particles, a deviation of mean values of magnetic flux and virtual current densities outside particles and a distortion of magnetic and virtual current fields in surroundings of particles.The magnetic particles with electric conductivity considerably greater than fluid conductivity are especially dangerous. A relative error in this case may exceed volume concentration of particles six times.For non-magnetic particles measurement error is absent independent of their conductivity.